Why is Sutro Better?

We get this question all the time and it’s time we answered it!

Fives Years And Two Continents Development

Sutro started 5 years ago. Ravi Kurani, our founder and CEO, had an idea — how to “fix” water.

Ravi worked at his dad Harry’s pool store when he was a kid. He was also a pool boy who has probably done way over 10,000 manual tests in his lifetime. Ravi knew that the majority of problems that he had to fix were due to inconsistent pool testing. Roughly his Dad’s shop would get panicked, customers would call that their pool was green, or foaming, or smelled funny and that they needed to get their water fixed pronto.

Ravi went to college in Riverside and got a degree in Mechanical Engineering. He was, albeit briefly, a rocket scientist with NASA (JPL to be exact), working on a more effective way to burn rocket fuel. Sounds fun huh :-).

Ravi’s curiosity and entrepreneurial spirit led him to India where he worked on solving the problems with contaminated water. It turns out that the majority of the world’s problems revolve around having access to clean water.

Insight #1: Be an Expert in What You’re Trying to Solve 

It’s All About What’s in the Water

Ravi’s adventures in India gave him the idea that before you can treat water, you have to test it to see what’s wrong with it. Sounds simple enough but you’d be surprised that no one was doing that. The problem, as Ravi will tell you, is trying to sell a new technology to a government is like climbing a pole slick with grease — you never seem to get anywhere.

Once Ravi came back home, he realized that his ambitions to make water safe had to start small — like the size of your backyard pool; small.

A Backyard Chemistry Experiment

If you have a pool (or spa for that matter), you know that it’s really a large backyard chemistry experiment that will test your mental and physical patience and prowess. Water is complicated. Even though it’s a simple bonding of Two Hydrogens and One Oxygen and it makes life on earth possible. In fact, it’s essential for every single living thing on planet earth including green, mustard, and black algae that live in an untreated pool.

Your backyard chemistry experiment is complex and needs a lot of TLC in order to make it safe for you to swim. Ravi’s experience taking care of over a 1,000 pools taught him that consistent testing, that’s accurate, will keep your pool (or spa) water safe. That led him to develop the first Sutro prototype.

Insight #2: Take a manual process and automate it to make it repeatable and more accurate.

The Problem with ORP

The first Sutro Smart Monitor used a technology called ORP (you can see our demo at TechCrunch back in 2015 at CES’s Hardware Battlefield). The two wires sticking out of the chlorine floater are nothing but a pH and ORP sensor. ORP stands for Oxidation-Reduction Potential. It measures the oxidizing properties of any sanitizer present in the water. When chlorine is free to oxidize, sensors generate a millivolt reading, expressed as ORP. If the chlorine isn’t free and available, a millivolt reading will not be generated. At the time, ORP was the go-to method to measure this because it was electronic meaning you did not have to do the manual process of dropping chemicals into a flask of water.

The problem with ORP (which Ravi figured out 3 years ago) is that it drifts all over the place and the sensor needs to be calibrated with a known standard. This is cumbersome and leads to all sorts of inconsistencies in measurements.

As an example, ORP measurements vary by time of day since sunlight (actually the UV part of sunlight) will cause cyanuric acid (CYA) and chlorine to combine, which makes the chlorine less free to do its job. It still can mind you, but any ORP reading will “show” that it can’t. Or that the pump running can send signals through the water which will affect ORP and cause it to go wacky. Kind of like passing through a metal detector if you have a pacemaker or a titanium hip.

The first ORP Smart Monitor had lots of problems that nearly bankrupted Sutro. It was only through Ravi’s hard work, pool boy experience, and mechanical engineering background that he realized the best way to test water would be to create a “mini pool boy” robot (like the Roomba vacuum). He thought why not take the dropping chemicals in a tube of water and create a robot that would do it.

Insight #3: The “easy” way did not cut it and was wildly inaccurate.

A Roomba For Testing Water

You have probably seen a Roomba or know someone that has one. For those of you who don’t know what a Roomba is, it’s a robotic vacuum cleaner that learns your rooms and vacuums them automatically. It’s probably the best comparison we can draw for the Smart Monitor. Just imagine a Roomba in your pool sans the vacuuming.

The Roomba was first introduced in 2002 by a company called iRobot. iRobot was founded in 1990 by Massachusetts Institute of Technology roboticists with the vision of making practical robots a reality, iRobot has sold more than 30 million robots worldwide. Currently a Roomba sells for ~$299, depending on the model.

Robots Do a Lot of Work

Robots perform functions that humans can do as opposed to passive electronics or just a sensor. All this work, especially the moving of things in physical space, takes a lot more effort and smarts to make it work. If you compare the process of taking a Smart Monitor Measurement vs an ORP Measurement, you’ll see what I mean:

Smart Monitor	ORP Measurement
Prime Flow Cell Siphon Sample Titrate Sample Measure Color Calculate Result Report Result	Measure Potential Calculate Result Report Result

The first part of our process relates to taking in an actual sample of the water and adding drops of reagents — just like you would do with your home kit. That’s the robot part and while it’s more complicated (and costly), it’s the most accurate way to do it.